Device for administering of medication in fluid form

ABSTRACT

An infusion device for continuous infusion of medication is disclosed, in which infusion is controlled over two separate fluid communications. The infusion is in each fluid communication controlled by restricting means and valve means, and one of the fluid communications farther contains a holding device for bolus rate of infusion for a short period. The device comprises a flow regulating device comprising a passage defined by at least a first element and a second element, wherein at least one of the first and second element is a primary deformable element adapted to be elastically deformed so as to change the cross sectional area of the passage. Furthermore the device comprises a container for storage and supply of a medication in fluid form, said container comprising a first and a second chamber being arranged relatively to each other so that when volume of the first chamber Increases the volume of the second chamber decreases.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is entitled to the benefit of and incorporates byreference essential subject matter disclosed in InternationalApplication No. PCT/DK03/00107 filed on Feb. 18,2003, Danish PatentApplication No. PA 2002 00240 filed on Feb. 18, 2002, and Danish PatentApplication No. PA 2002 00970 filed on Jun. 25, 2002.

FIELD OF THE INVENTION

The present invention relates to a device for administering a medicationand more specifically to a safe construction for administering amedication in fluid form and in particular to a device for administeringa medication with a sensitive structure. Furthermore the presentinvention relates to valve and in particular to a valve suitable foradministering small doses of a fluid.

BACKGROUND OF THE INVENTION

Administering systems for continuous administering of a medication influid form are known in the art, and used in hospitals. The purpose forsuch devices is to give the patient the freedom of movement, even thoughhe is connected to a device for administering of a medication e.g. byinfusion. The adjustment of the rate of discharge from such devicestakes place only by adjusting the dosage by hand, and is done by thepersonnel at the hospital as a part of the treatment of the patient.

Administering systems for controlled administering of fluid basedmedication, outside hospitals is also known in the art. Such systems maywork by moving a piston in controlled steps, leading to infusion inbatches. A plurality of pump devices for administering of insulin todiabetic patient used to day is based on infusion in controlled steps.The medication is administered into tissue, from which the medicationdiffuses into the blood.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a device forcontinuous administering of fluid based medication, wherein theadministering is controllable, and where the infusion during any faultsituation in the device is unable to harm the patient.

A further object of the present invention may be to provide a devicewhich may be able to administer medication in two types of doses—a basaldose and a bolus dose. Furthermore it may be an object of a preferredembodiment of the present invention to provide a device wherein the flowof medication in the device may be monitored.

According to a first aspect the present invention relates to a devicefor administering of a medication in fluid form, said device comprisingan outlet means and a storage means for storage of a fluid, said devicefurther comprising,

-   -   two individual communications each of which being in fluid        communication with the storage means and the outlet means,    -   each communication comprising at least one flow restricting        means,    -   at least one valve means arranged down stream the storage means        and upstream at least one flow restricting means, and        wherein at least one of said individual communications comprises        a holding means intermediate the storage means and the valve        means, said holding means being in fluid communication with said        storage means over at least one restriction means.

The fluid of the device may contain a medication or maybe any otherfluid such as a saline solution. The device may be adapted to restrictthe rate at which a medication is administered e.g. discharged thoughtthe outlet of the device. The outlet may be connected to a cannula or toa tube connected to a cannula.

At least a part of the device may be adapted to be positioned in a bodyof a mammal e.g. a human being, for shorter or longer period. In someembodiments only a cannula is placed in the human body and the rest ofthe device is placed outside the body. In some embodiments the storagemeans may be adapted for accommodation in a human body and thusrefilling of the storage means may be done by means of a needle insertedthrough the skin of the human being or mammal.

The medication comprised in the fluid may be insulin or hormones or ananti-inflammatoric medication. The two communications may be inindividual fluid communication with the storage means and the outletmeans. In some embodiments a part of each of the two communications maybe provided by the same tube such that said tube branches out into twoseparate communications. The two communications may branch out and mergein different locations on the individual communications.

The restriction means may be provided by small tubes e.g. capillariesadapted to restrict the flow. In an embodiment all restricting means areprovided as capillaries. The capillaries may have different internaldiameters so as to allow different flow rates. In an embodiment at leastone of the capillaries is provided by a piezoelectric element adapted tochange the internal diameter such that the flow rate of said capillarymay be varied. Such a piezoelectric element may be annular.

The cross-sectional area of at least one of the capillaries may bebetween 10 μm² and 50 μm², such as between 15 μm² and 30 μm², such as 20μm2. The length of the capillaries may be used to design the desiredpressure drop over the capillary. Thus the small capillaries of thepresent invention e.g. the capillary used for the basal dose, may have alength of between 30 mm and 100 mm, such as between 40 mm and 80 mm,such as between 50 mm and 70 mm, such as 66 mm. In order to reduce thephysical extend of the capillary the capillary may be U-shaped or defineany other shape reducing the physical extend of the capillary.

The length of the larger capillary e.g. the capillary upstream of theholding means may be 3-10 times shorter than the aforementionedcapillary, such as between 5 and 8 times shorter. The length of thecapillary may be adapted to the individual person who uses the device.The size of the capillary may be chosen with regard to data of theperson such as size, weight, metabolism, the average size of meals eatenby the person etc.

In an embodiment the capillaries may be provided in units having lengthsof 10 mm such that joining the capillaries in series may provide adesired length. Thus the ends of units may be adapted for attachment toeach other. According to the first aspect of the invention thecapillaries and the valve means may be provided in a surface of asubstrate comprising silicon. Thus the first and/or the secondindividual communication may be provided in the silicon substrate.

The invention according to the first aspect may comprise one valve. Thevalve may be arranged in one of the two communications or a valve may beprovided in each of the two communications. By providing a valve it maybe possible to control the administering of medication even moreprecisely as the flow in one or both of the individual communicationsmay be shut off and turned on in any desired pattern.

In the present application a restriction means is defined as a means forrestricting the flow rate. A restriction means may vary the flow rateand thus be adjustable.

In the present application a valve means is defined as a means which isable to shut off the flow completely. Thus a valve may be set in anyposition between two opposite positions, the open position and theclosed position, i.e. valve may be set in any intermediate position. Avalve may thus be seen as a restriction means which can be shut off.

In the present invention a communication is defined as any path whereina fluid may flow.

At least one of the individual communications comprises a holding means.Said holding means may be adapted to store a predetermined amount ofmedication of fluid such that a larger dose of medication or fluid maybe administered. In some embodiments, both the individual communicationsmay comprise separate holding means such that each of the twocommunications may be used for administering a larger dose. Thus if thetwo individual communications provide passage for different types ofmedications, larger doses of each of the two medications may beadministered individually. As an example, one of the two communicationsmay be in fluid connection with fluid comprising insulin, while theother communication is in fluid communication with a glucose solution.Should an overdose of insulin be administered, the holding member of thecommunication providing passage for glucose may be used to eliminate theundesired effects of the overdose. The two communications may providepassage for any complementary medications.

The device may comprise means for pressurising said storage means. Suchmeans may be an elastic member provided around the storage means. Inother embodiments the means for pressurising may be provided aselectrically actuated actuation means or a pressure compartment adaptedto apply a pressure on the storage means.

It may be desirable to be able to monitor the administering ofmedication. Thus at least one of said restricting means may comprisedetection means adapted to supervise the flow in the restricting means.The detection means may be an impeller or any other device forsupervising a flow. In an embodiment the detection means may be adaptedto detect a pressure difference between a supply-side and adischarge-side of the restriction means.

The supply-side may in some embodiments be seen as directly at theinlet, while in other embodiments the supply-side may be seen as an areain the vicinity of the inlet. In yet other embodiments the supply-sidemay be seen as anywhere between the inlet and another element in thecommunication e.g. the first upstream element.

The discharge-side may in some embodiments be seen as directly at theoutlet, while in other embodiments the discharge-side may be seen as anarea in the vicinity of the outlet. In yet other embodiments thedischarge-side may be seen as anywhere between the outlet and anotherelement in the communication e.g. the first downstream element.

In some embodiments only some of the restriction means are provided witha detecting means whereas in other embodiments all restriction means areprovided with detection means.

As the flow is monitored it may be possible for a control means tomonitor the amount of medication or fluid which is administered.

The detection means may comprise a membrane adapted to move between afirst position and a second position, each side of said membrane may bein fluid communication with an inlet and/or an outlet of a restrictingmeans. Thus the position of the membrane may be used as an indicator forthe pressure difference between the first and the second position.

In some embodiments at least one of the detection means may be arrangedsuch that the pressure difference over two restriction means and/orvalves may be determined. In other embodiments each detecting means maybe in fluid communication with a supply-side and a discharge-side of oneof the restricting means, such that the pressure difference over onerestriction means is determined.

It may be desirable that the fluids on each side of the membrane are notin fluid connection. Thus the membrane may define a seal between asupply-side-chamber and a discharge-side-chamber. Thesupply-side-chamber and/or the discharge-side-chamber may be part of thedetection means. In some embodiments the discharge-side-chamber of afirst detection means may be a supply-side-chamber of a second detectionmeans or vice versa. In order to determine the pressure differencebetween the two chambers, the membrane may comprise an elastic material.Such a material may comprise a natural rubber material and/or asynthetic rubber material.

As the medication to be administered may have a molecule structure whichis so fragile that it may not be passed through the restriction meansthe device may comprise a separate container for storage and supply of amedication in fluid form. Said container may comprise a fluid chamberand a medication chamber being arranged relatively to each other so thatwhen volume of the fluid chamber increases the volume of the medicationchamber decreases. The container may comprise any feature or element ofthe second aspect of the present application.

The container may be arranged downstream at least one restriction meansand upstream the outlet means. In one embodiment the container may bearranged downstream all the restriction means and upstream the outletmeans. In the latter embodiment the fluid chamber may be in fluidcommunication with any restriction means and outlet means may be incommunication with the medication chamber.

An advantage of the above mentioned container may be seen as eliminatingany passing of the medication through a restriction means. Thus anyother fluid e.g. a saline solution may be used to pressurise themedication chamber of the container.

In one embodiment the two individual communications may define a firstand a second communication and wherein the first communication may beadapted for administering of a basal rate medication and the secondcommunication may be adapted for administering of a bolus rate ofmedication. As the second communication is adapted for dosing of a bolusrate of medication it may comprise the holding means. Thus while thevalve is closed the holding means may be filled up and as a restrictionmeans may be provided upstream the holding means the filling rate may below. When the valve is opened and the holding means is emptied the bolusrate of medication may be administered.

The holding means may comprise a chargeable accumulator adapted to becharged with fluid.

At least one of the aforementioned valve means may comprise:

-   -   a passage defined by at least a first element and a second        element, wherein at least one of the first and second element is        adapted to be elastically deformed so as to change the cross        sectional area of the passage. In some embodiments all the        valves of the device are made according to the above-mentioned        description. Said valves may comprise any feature or element of        the third aspect of the present invention.

In an embodiment of the first aspect of the present application thedevice may further comprise control means adapted to control theadministering of medication. Such a control means may comprise a firstcomputer system, the computer system comprising input means forcollecting data in a first format, processing means for processing thedata, output means for presenting data in a second format, and datastorage means having stored therein a computer program.

The computer system may comprise an operating system. The data collectedin the first format may be data from the detection means indication asto whether or not the flow in the system is according to thespecification. The data in the first format may be information e.g.provided by the user, about administering of the bolus rate and/or thebasal rate.

The data in the second format may be an alarm signal indicating that oneof the restriction means and/or one of the valves is out of order. Thedata in the second format may be control information used to control thevalve and/or the holding means. Accordingly in some embodiments thecontrol means may be adapted to control the storage means and/or theholding means and/or at least one valve of the device foradministration.

The control means may by operable by means of a separate control unit inwired and/or wireless connection with the device.

The computer program may be adapted to perform the steps of:

-   -   a opening of the valve means in the second communication    -   applying a pressure on the holding means so as to administer the        bolus rate    -   closing the valve means in the second communication.

Furthermore the computer program may be adapted to remove the pressureon the holding means, so as to allow said means to be filled with a newbolus rate.

According to the first aspect of the invention medication may be infusedat a rate controlled by one of the two communications, and the holdingmeans may give the possibility of infusing a bolus rate of medicationfor a short period. The continuously rate of infusion the device is ableto discharge, in case of all control are lost, is balanced to thepatient, whereby the worst case fault situation is unable to harm thepatient.

The restricting means of the infusion device may be supplied withdetection means, supervising the infusion of medication. Hereby may beachieved that the control system receives information to evaluate theinfusion situation, and hereby may be able to detect an infusionfailure.

In a specific embodiment of the invention, a membrane may form thedetection means, where each side of the membrane may be in fluidcommunication with each side of the restricting means. Hereby may beachieved that the direction of the deflection of said membrane mayindicate the direction of pressure over said restricting means.

In another specific embodiment of the invention, separate pressuredetectors may form detection means, each may be in pressurecommunication with supply side or discharge side of one of saidrestriction means. Hereby is achieved that the pressure detection cantake place locally in the infusion communication pad, without anyadditional fluid communications being needed.

A membrane on the detecting means may seal a closed area comprisingliquid, and an elastic element may give the membrane and the liquid thepossibility of moving in accordance with a pressure rise on the side ofthe membrane facing away from said liquid, and the movement of liquidmay be detectable. Hereby may be achieved that the medication may bekept inside the infusion communication, and only the pressure may betransported, via the membrane, to the liquid. This gives access todifferent ways for detecting the movement of the liquid, as noconsiderations regarding the impact from the medications itself has tobe taken, besides from the choice of membrane material.

In a further specific embodiment, capillaries may form the restrictingmeans in the infusion device. Hereby may be achieved that the rate ofinfusion may be well defined in relation to the pressure acting on eachside of a restricting means.

The infusion device may contain storage means for medication, thisstorage means for medication may be pressurised by fluid from a separatepart of the infusion device, whereby the rate at which medicationdischarge through the outlet means may depend on the rate at which fluidpressurises the storage means for medication. Hereby may be achievedthat the medication may be infused directly from the storage compartmentto the outlet of the infusion device, without passing any valves andrestricting means. For sensitive medications this could be an advantage.

In a specific embodiment of the invention, one of the two individualcommunications may restrict the rate at which medication from onestorage means for medication discharges, and the other of the twoindividual communications may restrict the rate at which medication fromanother storage means for medication discharges. Hereby may be achievedthat medication of different strength or different response time may bedischarged from the device.

It may be seen as an advantage that the two individual communicationsmay form a first communication for basal rate of infusion of medicationand a second communication for bolus rate of infusion of medication, andwhere the holding means may be contained in the second communication.The medication may hereby be able to infuse at controlled rates,depending on the actual and present need.

In an embodiment the first aspect of the present invention may relate toa device for infusion of medication, said device containing:

-   -   storage means for storage of fluid,    -   outlet means for infusion of medication,    -   means for pressurising said storage means,    -   means for restricting the rate at which medication discharge        through said outlet means,    -   valve means disposed intermediate said storage means and said        restricting means,        wherein two individual communications expose separate means for        restricting the rate at which medication discharge through said        outlet means, and in that one of said individual communications        contains holding means intermediate said storage means and said        valve means, said holding means being in fluid communication        with said storage means over separate restriction means.

Said restricting means may be supplied with detection means, wherebyinfusion of medication is supervised.

Said detection means may be formed by a membrane, each side of saidmembrane being in fluid communication with each side of said restrictingmeans, whereby the direction of the deflection of said membrane willindicate the direction of pressure over said restricting means.

The separate pressure detectors may form said detection means, each inpressure communication with supply side or discharge side of one of saidrestriction means.

A membrane may seal a closed area containing liquid, and that an elasticelement may give said membrane and said liquid the possibility of movingin accordance with a pressure rise on the side of the membrane facingaway from said liquid, said moving of liquid being detectable.

Said restricting means may be formed by capillaries.

Said fluid in said storage means may be the medication.

The device may contain storage means for medication, said storage meansfor medication being pressurised by fluid from said storage means forfluid, whereby the rate at which medication discharges through saidoutlet means may depend on the rate at which fluid pressurizes saidstorage means for medication.

One of said two individual communication may restrict the rate at whichmedication from one storage means for medication discharges, and theother of said two individual communication may restrict the rate atwhich medication from another storage means for medication discharge.

Said two individual communications may form a first communication forbasal rate of infusion of medication and a second communication forbolus rate of infusion of medication, and where said holding means maybe contained in said second communication.

Said holding means may form a chargeable accumulator, charge with fluidfrom said storage means over said separate restriction means, while saidvalve means in second communication is closed.

An opening of said valve means in said second communication may allowsaid holding means to perform said bolus rate of infusion of medication,while said holding means depressurise through said valve means in secondcommunication, where after the rate of infusion of medication in saidsecond communication may drop to a lower level controlled by saidseparate restriction means.

Said valve means may be formed by an elastomer material, which underactuation from an actuator will deform into a part of saidcommunication, whereby flow of fluid may be prevented.

The invention according the first aspect of the invention may compriseany feature or element of the second and/or third aspect of theinvention.

According to a second aspect the present invention relates to a flowregulating device comprising:

-   -   a passage defined by at least a first element and a second        element, wherein at least one of the first and second element is        a primary deformable element adapted to be elastically deformed        so as to change the cross sectional area of the passage.

In some embodiments the first element is a primary deformable element,while in others the second element is a primary deformable element. Yetin other embodiments both the first and the second elements are primarydeformable elements. In the latter case a half circle may be defined inboth the elements such that the two half circles together define acircle. When the two elements are deformed the cross-sectional area ofthe circle may be deformed.

The primary deformable elements may be adapted to be changed between twopositions a first position wherein the cross-sectional area is as big aspossible and a second position wherein the cross-sectional area is assmall as possible e.g. close to zero.

In an embodiment at least a part of the primary deformable element inthe first position encircles at least a part of the passage.

When force is applied to the deformable element, the element may changefrom the first position to the second position or any intermediateposition. Thus the force applied to the deformable element may be usedto control the cross-sectional area of the passage.

In some embodiments a force in the direction of the centre of thepassage may be applied in order to change the cross-sectional area ofsaid passage. In other embodiments forces may applied on two sides ofthe primary deformable element. A force zone may then be defined betweenthe forces and in some embodiments the passage may not be defined in theforce zone. Thus the primary deformable element may be deformed in afirst direction when a force is applied in a second direction, the firstdirection being transverse to the second direction.

A secondary deformable element may encircle the primary deformableelement. The secondary deformable element may be harder than the primarydeformable element. Thus the secondary deformable element may be adaptedto work as an outer wall of the primary element. The secondarydeformable element may in some embodiments be hard enough to retain itsshape without any support from other elements. In other embodiments thesecondary deformable element may not be hard enough to retain its shapewithout any support and therefore a supporting element may be providedaround the second deformable element. The softer the primary element isthe easier it may be for the element to block the passage. In someembodiments the primary deformable element may be an oil or water orair. In some embodiments the primary and/or the secondary element maycomprise an elastomer e.g. silicone. When choosing the elastomer it isessential that the elastomer and the medication may work togetherwithout damaging each other.

A membrane may be provided between the first and the second elements.Such a membrane may be adapted to provide a seal such that the primaryelement and/or the secondary element may not come in contact with thecontent of the passage e.g. a medication in fluid form. Thus themembrane may provide a seal between the first and the second elements.The membrane may comprise a natural rubber material and/or a syntheticrubber material.

The area of the passage may be between 0.1 mm² and 1 mm², such asbetween 0.2 mm² and 0.7 mm², such as between 0.25 mm² and 0.5 mm². Itmay be desirable to choose a cross-sectional area at any place of theindividual communication that is as small as possible,, as the totalvolume in the two individual communications may then be limited. Thesmaller the total volume of the individual communications, the easier itmay be to control the system. On the other hand, the cross-sectionalareas may not be so small that the resistance in the system is too big.Only in the restriction means may the resistance be desired to be small.

According to the second aspect of the invention a device may be providedin which a valve means may be formed by an elastomer material, whichunder actuation from an actuator may deform into a part of saidcommunication, whereby flow of fluid may be prevented.

The invention according to the second aspect of the present inventionmay comprise any feature or element of the first and/or third aspect ofthe invention.

According to a third aspect the present invention relates to a containerfor storage and supply of a medication in fluid form, said containercomprising a first and a second chamber being arranged relatively toeach other so that when volume of the first chamber increases the volumeof the second chamber decreases.

In an embodiment the first chamber and the second chamber areinterconnected by a hydraulic system e.g. comprising a saline solution.Thus the hydraulic liquid may be used to change the volumes of the twochambers e.g. by moving pistons in each chamber.

Furthermore at least a part of a sidewall separating the first andsecond chamber may movable. Thus in one embodiment only one wallseparates the first and the second chamber and said wall may work as apiston.

In other embodiments at least a part of a sidewall separating the firstand second chamber may be flexible. Thus a bag-like element defining thesecondary chamber may be provided in a large chamber. The part of thelarge chamber, which is not filled with the bag-like element, may definethe primary chamber. When the primary chamber is filled with a fluid thesecondary chamber in the bag-like element collapses and fluid in the bagmay be administered. In some embodiments the bag-like element definesthe primary chamber and the rest of the large chamber defines thesecondary element.

The first chamber may be a fluid chamber adapted for storage of a fluide.g. a saline solution and the second chamber may be a medicationchamber for storage of medication. The saline solution may be anisotonic solution which does not change the balance of salts on theblood.

In general it may be seen as an advantage to choose elements and fluidswhich does not damage each other and which may be inserted oradministered in the human body.

The third aspect of the present invention may comprise any feature orelement of the first and/or second aspect of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described in details withreference to the drawing in which:

FIG. 1 shows a device according to the first aspect of the invention,

FIG. 2 shows a device for administering of medication comprising flowdetectors,

FIG. 3 shows a flow detector according to the first aspect of theinvention,

FIG. 4 shows a principal embodiment of the invention, where themedication itself is contained separate from the infusion controlsystem,

FIGS. 5 and 6 show a flow regulating device according to the secondaspect of the invention,

FIG. 6 shows a detailed view of an embodiment of a valve for theinfusion control system, shown in closed position,

FIG. 7 shows an embodiment wherein medication is discharged from twoseparate compartments,

FIG. 8 shows a embodiment of a pressure detection means, and

FIG. 9 A principal view of a flow detector, showing different possibledetecting results in picture A-E.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 is shown an infusion device for administering of medication influid form, e.g. infusion of insulin to a diabetic patient. The devicecomprises a storage compartment 1, in which the medication is contained.The storage compartment 1 is made as a sealed bag with an outlet 3,through which medication can be discharged from the bag simply by addinga force external to the sides of the bag.

The compartment 1 is surrounded by an elastomer pressure jacket 2, whichwill apply a nearly constant force to the compartment, until being emptyof medication. The pressure of the medication at the outlet 3 is herebyheld constant, until the compartment 1 is emptied for medication. Theoutlet 3 is in connection with an outlet 4 from the device, from wherethe medication is administered e.g. infused.

The outlet 4 is in fluid communication with the compartment 1 over twoindividual communications 5 and 6, each having a valve 7 and 8 and acapillary 9 and 10. The capillary 9 has a small diameter, which willcorrespond to a low rate of discharge of medication, referred to as thebasal rate. For diabetic patients this corresponds to the low rate ofinsulin discharge, which will balance the glucose level under normalconditions between meals. Adjustment of rate of discharge throughcapillary 9 can take place by adjustment of the valve 7. In someembodiments the valve 7 may be controlled between a fully open and afully closed position, like a pulse modulation with adjustable duty ratein a fixed duty cycle. A high duty rate will then correspond to a highrate of discharge, however still within the basal rate.

The capillary 10 in communication 6 has a diameter larger than thediameter of the capillary 9. Thus the capillary 10 is able to dischargemedication at a rate referred to as the bolus rate. For diabeticpatients this corresponds to the high rate of insulin discharge, whichwill balance the glucose level during and right after meals. Adjustmentof rate of discharge through capillary 10 can take place by adjustmentof the valve 8. In some embodiments the valve 8 may be controlledbetween a fully open and a fully closed position, like a pulsemodulation with adjustable duty rate in a fixed duty cycle. A high dutyrate will then correspond to a high rate of discharge, and a low dutyrate to a low rate of discharge, however still within the bolus rate.

In case of a valve failure of valve 7, causing the valve to jam in openposition, the control of the basal rate will be lost. This may, relatedto infusion of insulin, cause a slightly over dosing of insulin betweenthe meals, but will have no harmful effect on the diabetic patient. Ifthe failure however was on valve 8, still jam in open position, thebolus rate of discharge will have a deadly effect on the diabeticpatient.

In order to prevent the bolus rate of discharge to be uncontrolled, thecommunication 6 comprises a separate capillary 11, which will restrictthe rate of discharge from compartment 1 through communication 6 tooutlet 4, in case the valve 8 is jam in open position. The effect of thevalve 8 being jam in open position will now be an uncontrolled bolusrate of discharge, but restricted to a low value. The capillary 11 mayrestrict the rate of discharge to a value correspond to the normal bolusinfusion over a day, if this was to be infused continuously.

Under normal operation of the communication 6, valve 8 will be closedfor a long period between the meals. In this period medication dischargefrom compartment 1, through capillary 11 to compartment 12, which is asmall sealed bag in fluid communication with compartment 1, and with anelastomer pressure jacket 13, surrounding the compartment 12. Thiscompartment 12 with pressure jacket 13 is referred to as a holdingdevice, and works as an accumulator in hydraulic systems. The pressurein compartment 1 and compartment 12 will equalise during the closeperiod for valve 8, and as valve 8 is opened the bolus rate of dischargewill be high, as only capillary 10 restricts the rate of discharge fromcompartment 12 to outlet 4 in FIG. 1.

A valve failure will have an uncontrolled rate of discharge as result,but the rate of discharge will be restricted to a normal level ofinfusion over a day. The patient might feel a slightly uncomfortably,but will in no way be harmed by the valve failure.

The device of FIG. 1 is a wet disposable device, containing themedication in fluid form (e.g. insulin), the tubing, the capillaries,the valves and the holding device. The wet disposable device may containother needed elements of the infusion device, such as actuating meansfor the valves and the elastomer pressure jackets. As the wet device isdisposable, all elements, which are not in direct contact with themedication, could be contained in a control device, and the controldevice and the wet device could be connected in a way that makes reuseof the control device possible.

In FIG. 2 is shown a infusion device similar to the device of FIG. 1. InFIG. 2 each of the capillaries 9 and 10 are divided into two seriesconnected capillaries, 9 a, 9 b and 10 a, 10 b respectively. Except from9 a, 9 b, 10 a and 10 b all reference numbers from FIG. 1 apply to FIG.2. The two series connected capillaries, 9 a, 9 b and 10 a, 10 b, ofFIG. 2 are each supplied with a detection device 14 and 15. Thedetection devices 14 and 15 are identical, and only detection device 14is to be explained in details.

Flow of medication over capillary 9 a will have a pressure drop asconsequence, and this pressure drop is detected between connection 16and 17. Pressure drop over capillary 9 b is detected between connection17 and 18. The connection 16 is in fluid communication with compartment19 in the detector device 14, see FIG. 3, the connection 17 withcompartment 20 and the connection 18 with compartment 21. Thecompartments 19-21 are formed by lamination of to parts 22 and 23, withdeflectable membranes 24 and 25 between. The structure of the surface ofeach of the two parts is, on the side facing the membranes 24 and 25,such that the compartments 19-21 will be formed as the lamination hastaken place.

Each membrane 24 and 25 is able to deflect upwards, indicated asposition 26, or downwards, indicated as position 27. Detection means isable to detect between even position, upward position and downwardposition, and able to detect on each membrane separately. This detectionmeans could simply be an optical detector, which sees the direction of adeflection. A normal infusion will have a pressure drop betweencompartment 19 and 20, and between compartment 20 and 21, as result.Normal infusion will therefore be detected as an upward deflection ofmembrane 24 and a downward deflection of membrane 25.

The table below indicates all possible detections results, and thesituation leading to the result.

Membrane 24 Membrane 25 Situation Even Even No flow Upward Even 9ablocked Downward Even Error Even Upward Back pressure Upward Upward LeakDownward Upward Back flow Even Downward 9b blocked Upward DownwardNormal flow Downward Downward Error

As it may be seen from the above table the application of twocapillaries and corresponding means for detecting pressure differencesover said capillaries provides the advantage that blockage of each ofthe communication may be detected. If only one capillary withcorresponding pressure detecting means is provided, blocking of thecapillary may be detected as a normal functioning capillary. This is dueto the fact that a pressure difference is present over a blockedcapillary.

The communications 5 and 6 of FIGS. 1 and 2 consists of fluid channels,by which the storage compartment communicates with capillaries andvalves. The valves 7 and 8 have the purpose of blocking one such fluidchannel, which is shown at FIGS. 5 and 6. The valves, which are providedaccording to the second aspect of the present invention, are used inembodiments according to the first aspect of the invention.

The valve 32 of FIG. 5 is formed as a block, which is placed over afluid channel 33, made by removing of material from a solid block 34 orby molding the block 34 with the channel 33. This solid block 34 is theinfusion manifold of the infusion device of FIGS. 1 or 2. Between thesolid block 34 and the valve block 32 is provided a membrane, which isable to deflect into the fluid channel 33. This deflection is indicatedat FIG. 6.

The valve block 32 is held against the solid block 34 by a force 36,which is acting on a solid material part 37. The valve member 38 isformed by a soft elastomer, contained within a case of a hard butdeformable elastomer 39. The hard elastomer 39 is held in shape by asolid ring member 40 at the lower end, and by a moveable ring member 41at the upper end. As a force 42 is applied to the ring member 41, thehard elastomer 39 is deformed, and the soft elastomer 38 is pressedtowards the membrane 35 and into the fluid channel 33. Fluid passage ishereby prevented, as the valve member is closed.

In FIG. 7 an infusion device like that of FIG. 2 is shown, but with themedication contained in two compartments, 1 a and 1 b. Each of the twocompartments 1 a and 1 b are supplied with a elastomer pressure jacket 2a and 2 b, and have a separate outlet 3 a and 3 b. The medicationdischarged from outlet 4 through communication 5 can hereby be differentfrom the medication discharged from outlet 4 through communication 6.For diabetic patient, the basal rate of infusion could be with one typeof insulin, and the bolus rate of infusion could be with a more powerfull or with a faster acting type of insulin, whereby a detected drop inthe glucose level for the patient quickly could be compensated withinfusion of a bolus rate.

In FIGS. 1, 2 and 7 an infusion device where the medication itself isforced through capillaries, valves and pressure variations has beenshown. Some medications consist of molecules with a very sensitivestructure, i.e. insulin. Those medications may be too sensitive to copewith the influences from the infusion device of FIGS. 1 and 2. In FIG. 4however, an infusion device, having a storage compartment 1 formedication, and being in connection with an outlet 4 from the device, isshown. The storage compartment 1 is made as a sealed bag with an outlet3, where the medication can be discharged from the bag simply by addinga external force to the bag. This external force is applied bypressurising the container 28.

Controlling the pressure in the container 28 controls the rate ofinfusion of medication from compartment 1, and medication is thereforeonly contained in a small part of the infusion device, this part beingindicated as position 29. Position 30 indicates the part of the infusiondevice for pressurising the container 28, and is the device shown inFIG. 2. The fluid in compartment 31 is not a medication, but a suitablefluid for pressurising the container 28 e.g. a saline solution. Apartfrom that, the function of device part 30 is similar to that of FIG. 2,and shall therefore not be described further.

FIG. 8 shows an alternative pressure detecting device 43 to that of FIG.3. A membrane 44 seals a pipe-shaped element 48, whereby a closedcompartment inside the pipe-shaped element exists. One part 45 of theclosed compartment is filled with a liquid, and another part 47 isfilled with air. A plunger element 46 seals the air-part 47 from theliquid part 45, and pressure acting on the membrane 44 will thus movethe plunger element 46, until a force equilibrium between membrane 44and air-part 47 arises. Detecting the movement of the plunger element 46will therefore correspond to detecting the pressure acting on themembrane.

The air-part 47 could be formed by a sealed bellow, whereby leaking ofair into the liquid-part 45 is prevented. It could also be formed simplyby a spring element, whereby only leaking of liquid into the spring-part47 is to be prevented. Of importance is only that liquid-part 45 ismovable within certain limitations.

The plunger element could be a second liquid, with different colour thanand not miscible with the liquid-part 45. Hereby is the interfacebetween the two liquids detectable, and will move due to pressurevariations on the membrane 44. A sealing element between liquid-part 45and air-part 47 will however still be needed, as totally filling of thepipe-shaped element 48 with liquid will make moving of the interfaceimpossible.

FIG. 9 indicates in picture A to E different detections results by useof the pressure detection device of FIG. 8. The infusion communication5, with the restricting element 9 a and 9 b, is supplied with a total ofthree pressure detectors 43, indicated as detector 49, 50 and 51. Thedetections results will hereby be:

Picture Detector 49 Detector 50 Detector 51 Situation A Centred CentredLeft No flow B Right Centred Left 9a blocked C Right Right Left 9bblocked D Right Right Right Back pressure E Right Right Centred Normalflow.

1. A device for administering a medication in fluid form, said devicecomprising: an outlet; a storage means for storing a fluid; first andsecond individual communications each of which being in fluidcommunication with said storage means and said outlet; eachcommunication comprising at least one flow restricting means forrestricting a flow, wherein said restricting means has no capability tostop the flow completely; at least one valve arranged influid-connection to at least one of said flow restricting means; andwherein the device downstream of said communications further comprises acontainer for storage and supply of a medication in fluid form, saidcontainer comprising a fluid chamber and a medication chamber beingarranged relative to each other so that when the volume of the fluidchamber increases the volume of the medication chamber decreases.
 2. Thedevice according to claim 1, further comprising a holding compartmentintermediate the storage means and the valve, said holding compartmentbeing in fluid communication with said storage means through at leastone of said flow restricting means.
 3. The device according to claim 2,wherein each of the two individual communications comprises at least onevalve.
 4. The device according to claim 2, wherein said holdingcompartment comprises a chargeable accumulator adapted to be chargedwith fluid.
 5. The device according to claim 1, further comprising meansfor pressurizing said storage means.
 6. The device according to claim 1,further comprising at least one detection device adapted to supervisethe flow in the restricting means.
 7. The device according to claim 6,wherein the detection device is adapted to detect a pressure differencebetween a supply-side and a discharge-side of the restricting means. 8.The device according to claim 1, wherein the at least one valvecomprises: a passage defined by at least a first element and a secondelement; and wherein at least one of the first and second elements isadapted to be elastically deformed so as to change the cross sectionalarea of the passage.
 9. The device according to claim 1, furthercomprising control means for controlling the administering ofmedication.
 10. The device according to claim 9, wherein the controlmeans comprises: a first computer system with an operating system, thecomputer system comprising input means for collecting data in a firstformat, processing means for processing the data, output means forpresenting data in a second format, and data storage means for storing acomputer program.
 11. The device according to claim 9, furthercomprising a holding device intermediate the storage means and thevalve, wherein the control means is adapted to control the storagemeans, the holding device, and at least one valve of the device foradministration.
 12. The device according to claim 11, wherein thecomputer program is adapted to control the steps of: opening the valvein the second communication; applying a pressure on the holding deviceso as to administer a bolus rate; and closing the valve in the secondcommunication.
 13. The device according to claim 9, wherein a separatecontrol unit operates the control means.
 14. The device according toclaim 13, wherein the control unit and the control means are adapted forwireless communication.
 15. A device for supervising flow comprising: afirst chamber, a second chamber and a third chamber, the first chamberbeing separated from the second chamber by a first membrane and from athird chamber by a second membrane; a first restricting means forrestricting flow having a supply-side in fluid communication with thesecond chamber and a discharge-side in fluid communication with thefirst chamber; and a second restricting means for restricting flowhaving a supply-side in fluid communication with the third chamber. 16.The device according to claim 15, wherein said first membrane and saidsecond membrane are each adapted to move between a first position and asecond position.
 17. The device according to claim 16, wherein saidfirst membrane defines a seal between the first chamber and the secondchamber and said second membrane defines a seal between the secondchamber and the third chamber.
 18. The device according to claim 15,wherein at least one of the first and second membranes comprises anelastic material.
 19. The device according to claim 15, furthercomprising means for detecting the position of said first and secondmembranes.